(i) Field of the Invention
The present invention relates to a method for preparing an alkoxyphthalocyanine which is useful as a novel recording material for optical discs or an intermediate of a novel phthalocyanine compound.
(ii) Description of the Related Art
Manufacturing methods of a 8-position substituted tetraalkoxyphthalocyanine having the formula (1): ##STR2## wherein --OR groups are substituted at the 2- or 3-position, the 6- or 7-position, the 10- or 11-position and the 14- or 15-position, are described in various literature. For example, the manufacturing process of 2,6,10,14-tetra-isopropoxyphthalocyanine is described in NOUVEAU JOURNAL DE CHIMIE, Vol. 6, p. 653-658 (1982). In this process, a diiminoisoindoline is mixed with N,N-dimethylaminoethanol and reaction is then carried out at 140.degree. C. for 22 hours. However, when this process is employed, the yield of the product is as low as 38%. Furthermore, as an example of the manufacturing process of an .alpha.-position substituted tetraalkoxyphthalocyanine which is substituted with -OR groups at the 1- or 4-position, the 5- or 8-position, the 9- or 12-position and the 13- or 16-position of the formula (1), Japanese Patent Laid-Open No. 62878/1991 (EP-0373643) discloses the manufacturing process of a 1,5,9,13-tetraalkoxyphthalocyanine in which n-amyl alcohol is mixed with phthalonitrile, palladium chloride, 1,8-diazabicyclo[5.4.0]-7-undecene (hereinafter abbreviated to "DBU"), and reaction is then carried out under reflux. Also in this process, however, the yield of the product is at a low level of 20%, and therefore the process is not industrially utilizable.